The relevance of the CO2 partial pressure of sodium bicarbonate solutions for the mass cultivation of the microalga Spirulina

Abstract

O meio de cultivo na base de bicarbonato de sódio usado para produzir a microalga Spirulina em massa e preparado seguinte ZARROUK 1 é meta-estável em contato com a atmosfera. Este fato causa uma grande perda de CO2. Com cálculos e experiências foi determinada a relação entre a pressão parcial de CO2 de soluções de bicarbonato de sódio e o pH da solução. Com pH 10.2 existe um equilíbrio com a concentração de CO2 no ar e desta maneira não há perda de CO2.It is demonstrated by experiments and calculations that the medium used for growing the microalga Spirulina (prepared according to ZARROUK 1 with a resulting pH of 8.7) is highly meta-stable in contact with the atmosphere and is thus loosing considerable amounts of CO2. This economic problem can be avoided by raising the pH of the culture medium to 10.2 where its partial pressure of CO2 corresponds to the partial pressure of CO2 in the atmosphere. The pH shift has practically no influence on the growth of the algae.

Spirulina sp. LEB-18 culture using effluent from the anaerobic digestion

“…bicarbonate is used, it represents 60% of the cost of nutrients (Alava et al, 1997), which is one of the reasons for studying the effects of lowering the concentration of the carbon source and finding alternative sources of this nutrient, such as molasses , residual CO 2 (Ferreira et al, 2012) and synthetic CO 2 (Rosa et al, 2011).…”

Perda química de carbono e cinética do crescimento celular em cultivos de Spirulina

“…Soluções ricas em carbono inorgânico dissolvido, como o meio Zarrouk, contêm CO 2 livre em concentração superior (0,05 g L -1 ) à de equilíbrio com a atmosfera (0,0004 g L -1 CO 2 a 30 °C). 21 Enquanto houver esse gradiente, ocorre um fluxo de CO 2 do meio de cultivo para a atmosfera.…”

Bio-Fixation of Carbon Dioxide using Carbonic Anhydrase through Synthesis of Bicarbonate

“…Alava et al [28] reported that if bicarbonate is used as carbon source, it represents 60% of the cost of nutrients for cultivation of algae. For autotrophic growth (which is more suitable for large-scale open cultivation of algae) carbon can be provided as carbon dioxide, carbonate or bicarbonate.…”